Problem: Solve for $f$ : $-\dfrac{3}{4}f=\dfrac{5}{4}$ $f =\,$
Answer: To divide both sides by $-\dfrac{3}{4}$, we multiply by the reciprocal $-\dfrac{4}{3}$ : $-\dfrac{3}{4}f {\cdot -\dfrac{4}{3}}=\dfrac{5}{4} {\cdot -\dfrac{4}{3}}$ To simplify, remember that when the signs are the same, the product is positive. When the signs are different, the product is negative. $\cancel{-\dfrac{3}{4}}f \cdot \cancel{-\dfrac{4}{3}}=-\dfrac{5}{3}$ $f = -\dfrac{5}{3}$